Vertical roller mills present a compact and efficient cement grinder method. Clinker and gypsum is ground on a rotating table that passes under large rollers. Material is forced off the table by centrifugal force, where it is then swept up into an airstream to a classifier immediately above. Just as with a ball mill, material that is too coarse is returned to the table for additional grinding while material that is fine enough is collected as product. The compact design of a vertical roller mill allows it to dry, grind, and classify, all within one piece of equipment and all in a relatively compact space.
A good substitute in place of glue or various kinds of cement for fastening emery cloth to the disks of grinders of the cement grinder type is to heat or warm the disk and apply a thin coating of beeswax; then put the emery cloth in place and allow to set and cool under pressure. If 1 part of thymol be mixed with 2 parts of iodoform we obtain a substance that retains its fluidity down to 72° C. (161.6° F.). If the temperature be carried down to 60° C. (140° F.) it suddenly becomes solid and hard. If, in its liquid condition, this substance be mixed intimately with an equal quantity of calcined bone, it forms a cement that can be molded or kneaded into any shape, that, at the temperature of the body (98° F.), becomes as hard as stone, a fact that suggests many useful purposes to which the mixture may be put.
Thin set cements are used for pool decks and decorative floors. When they need to be removed, a grinder is the perfect tool. The cement grinder can cut right through the thinset down to the original surface. For floors that are slightly unlevel, a grinder can correct this by removing a little of the surface. Also, joints that do not line up and create tripping hazards can be leveled out. Extreme differences would be corrected with a scarifier. Cement grinder can remove paint, epoxy and other materials that get onto cement are are difficult to remove.